Week 8~: 3D Printing

Hey hey! Welcome back to the blog!

For the holidays, we were tasked to create an object that can be 3D printed. However, it must be something that cannot be easily made subtractively. The general rule of thumb was that if we can laser cut it, then the object is not what we want. I even went to check the FabAcademy's website to check their requirements, and it even suggested a few possible techniques to use on the 3D printed product.

I was also given a 2 hour limit with the 3D printer. This was a challenge for me on the second half of the process, but i'll talk more about it in a bit. I booked a 2 hour slot for the 3D printer to maximise my time on one day.

I then went to make something with a mesh. A mesh is kind of like what you see on wire fences or windows, interlaced and quite uniform in nature. A product with a mesh can't really be easily made subtractively, especially if it's a 3D structure. Hence, I looked into that possibility and chose an object that has a function: a pencil holder!

This was my reference:

First off... Well, I didn't know how to make a mesh at the time. Thus, I went ahead and looked for tutorials online, and adapted from there. Here is how I made my personal pencil holder:

1) I first started by creating the base. I set the length parameter as 20mm to allow for quick changes later on. I used the fillet tool to curve the edges and even specified it as 1/8th of the length. 

2) I then created an offset inside the base to make the 'holder' part of the pencil holder. I specified 2mm offset as it was a pretty safe bet.

3) Using the extrude tool, I extruded the outer shape of the base by the height of 40mm. I extruded the base again as 4mm and changed the operation of the extrude to be 'Join' instead of 'New Body'. This would allow the base to create a visible line (which will be used later as our bottom boundary!) as shown here:

4) I then used the split body tool to create a top boundary. I first created an offset plane 4mm from the top face. Using the split body tool, I specified the body to split as our main body and the splitting tool as our offset plane. This would create a line right through the body, similar to the one at the bottom. I then smoothed out the top corners using the fillet tool once more.

5) On one side of the face, I created a small 'X' pattern, as shown here. I selected the side of the face and pressed the create sketch tool so as to make the face.  I specified a slight distance of 1mm away from the corner, and then created the 'X'. Afterwards, I specified the thickness of the pattern lines to be 1.5mm. 

6) Time to actually put the pattern into 3D space! I selected the 4 triangle faces on the sketch and used the extrude tool. I changed the operation from 'New Body' to 'Cut'. I used this technique so that in the event the wall thickness must change, the extrusion would not be completely messed up. It should look something like this:

7) Using the rectangular pattern tool, I repeated this 'X' pattern to the bottom of the pencil holder. I first selected the cut extrude and specified the directions to be on the horizontal and vertical sides of the face. I kind of had to rely on my instincts for this one and this is how it came out: I repeated the pattern 6 times vertically and 2 times horizontally, trying to get an even spacing in between.

8) I then wanted to make the same thing but on another face. Using the offset plane tool, I specified 1/2 of the length, and using the mirror tool, created the same 'X' pattern on the other side. It was important to select both the original 'X' pattern and the repeated 'X' pattern to make it complete! This was how it is:

I was worried about the printing time, hence I didn't really make it meshed on all 4 sides. Besides that, Voila! The pencil holder is complete. Here is the finished product:

After finalising everything, I then had to export the design into an .stl file so that the slicing app, Cura, can detect and use it for 3D printing. I pressed the file button and selected 'export'. The screen should look like this. I then specified the export file to be an .stl file. After the process was completed, it's time to start with the settings!

(oh, and here's the .stl file, if you're interested: https://tinyurl.com/holderSTL )

On Cura, I had specified the 3D printer used during set-up, which was Creality Ender-3. I then uploaded my newly downloaded .stl file into Cura. I then pressed the 'slice' button and found that it would take more than an hour to print... I was aiming to have the second hour as troubleshooting time.

I then had to scale down the design a good measure to bring the timing down. I then settled for a ~30min print using these settings:

I initially had very high infill settings but after a few test runs, I found that too much infill can cause the design itself to cool down too fast (as higher infill would take much longer per layer) and break off from the platform easily. Hence, I opted for a 10% infill.

On the day itself, the 3D printing process was simple. I had to export the .gcode from the Cura-sliced design into a thumbdrive holding an SD card, remove the SD card and place it into the 3D printer. Afterwards, I then selected the 'print' option on the 3D printer display screen and chose my design.

Here are some pictures of the 3D printing and the final product:

Welp... That's underwhelming. It wasn't able to serve it's purpose (unless it's a super small pencil. heh.) But hey, it's now, aesthetically, a tiny British phonebooth! 

All in all, I learnt how to use slicing tools and how to adjust my design accordingly to suit time constraints. I also learnt creating meshes for my design through the rectangular pattern tool. I was pleasantly surprised how user-friendly the 3D printer was, and I'm actually looking forward to using it once more.

Thank you for reading!